A drawbar spring includes a spring coil and two compression elements that, when the spring is under a tension load, operate to compress the spring coil. In one common drawbar spring configuration, the compression elements of a drawbar are loop elements that originate on opposite ends of the coil and pass through the center of the spring coil. Each loop element passes through the entire length of the spring coil and hooks on the opposite end of the spring coil.
When a drawbar spring is under a tension load, the loop elements are under tension and the spring coil is compressed. The configuration of a drawbar spring offers a built-in definite stop such that the drawbar spring can continue to carry a static load after reaching its maximum extended length. The definite stop is determined by the point at which the spring coil is fully compressed. Drawbar springs can also carry a static load if the spring coil fractures. For this reason, drawbar springs can be suitable for use in potential overload situations.
Drawbar springs including loop elements are available in a variety of standard sizes.